Acetyl-cellulose process and product.



l @TATE% PATENT @FFIfiE.

WILLIAM G. LINDSAY, OF NEWARK, NEW JERSEY. ASSIGNOR TO THE CELLULOIDCOMPANY, A CORPORATION OF NEW JERSEY,

ACETYL-CELLULOSE PROCESS AND PRODUCT.

No Drawing.

To all whom it may concern.

Be it known that-I, WILLIAM G. LINDSAY, a citizen of the United States,residing at Newark, in the county of Essex and State of New Jersey, haveinvented certain new and useful Improvements in Acetyl-CellulosePr'ocesses and Products, of which the following is a full, clear, andexact specification.

This invention relates to acetyl-cellulose and a process of makingthe'same. Its objectis to accomplish acetylation of the cellulose infibrous form, without solution of the cellulose, and withoutzthe use ofsulfuric acid, sulfo-acids, or other constituents tending to inducedecomposition.

' In practice I proceed as follows:

Cellulose, preferably high grade bleached cotton rovings, is given 'apreliminary treatment with acetic acid and zinc chlorid. For bestresults the cellulose should contain a normal amount of moisture,generally from 2% to 4%. I prefer about 3:}%. The

acetic acid should be about 90% strength,

and the zinc chlorid should be pure, free from iron and substantiallyanhydrous. A good example of proportions is cellulose 100 parts, aceticacid 200 parts and zinc chlorid parts. The zinc chlorid is dissolved inthe acetic acid at ordinary room temperature byagitation and thesolution thus produced is poured on to the cellulose contained in asuitable stoneware receptacle and allowed to penetrate. The position ofthe cellulose is changed from time to time and the reaction is allowedto proceed for forty-eight hours at a room temperature of from 60 to 70F.

After the foregoing preliminary treatment, the impregnated cellulose issubjected to the acetylating bath, which -consists of acetic anhydridand benzene. For best results the acetic 'anhydrid should be of thehighest commercial purity obtainableabout 925%. The benzene is of theso-called commercial chemically pure variety. A good example ofproportions, consistent with the forgoing proportions for preliminarytreatment, is acetic anhydrid 4.50 parts, benzene 1650 parts. The aceticanhydrid and benzene are mixed and the mixture warmedin a suitablevessel, such as an enameled steel kettle, to a temperature of about 150F. The preliminarily treated Specification of Letters Patent.

Patented Aug. 141., 1917.

Application fi1ed July 11, 1914. Serial No. 850,432.

an hour, and then slowly and gradually drops until the temperature ofthe water bath (150 F.) is reached. This ordinarily takes place in abouttwelve hours. lVhen this temperature has been reached the productmay beremoved from the bath, or the reaction may be continued, depending uponthe nature of the product desired. In many cases the product resultingfrom the reaction of twenty-four hours is desirable.

In the preliminary treatment, the bath of acetic acid, water and zincchlorid may be composed of any suitable equivalents for its ingredients,for example the water may be substituted by any other suitable hydroxylcontaining substance which, like water, is neutral with respect to thecellulose and miscible with the acetylizing bath but will act to induceacetylization; in place ofacetic acid other suitable diluent may beemployed, and in place of zinc chlorid as a condensing agent othersuitable inorganic salts may be employed.

At the end of the reaction period the product is freed from the spentacetylating liquor by any suitable means; for example, by whizzing or bypressing. After the bulk of the spent acetylating liquor has beenseparated from the acetyl-cellulose, the balance is then removed bywashing the acetyl-cellulose in hot water, or, if preferred, by meansof'a suitable vacuum machine.

The product thus obtained exhibits a physical form identical with theraw cotton, and is soluble in acetylene tetrachlorid, and withdifliculty in chloroform.

Having thus described my invention, I

declare that what I claim as new and desire to secure by Letters Patent1s I 1. The process of acetyliznigcellulose which consists in treatingcellulose with a agent, acetic acid and water,

acid condensing agent and is miscible with the acetylizing bath andwhich does not alter the cellulose as such and acts to induce lateracetylization, and then subjecting the.

treated cellulose to theaction of a non-solvent acetylating bathcontaining no additional condensing agent. 5. The process of acetylizingcellulose which consists in preliminary bath containin jzinc chlorid andan agent which acts to Induce acetylation without altering the celluloseas such and is miscible with the acetylizing bath, and then subjectingthe impregnated cellulose to the action of a non-solvent acetylatingbath. i

6. The process of acetylizing cellulose which consists in treatingapproximately '100 parts of cellulose with 200 parts of 90% acetic acidand 50 parts'of zinc chlorid, and

subjecting the impregnated cellulose to the action of anon-solventacetylizing bath.

' 7. The process of acetylizing cellulose which consists in treatingapproximately 100 parts of cellulose with 200 parts of 90% acetic acidand 50 parts of zinc chlorid, and subjecting the impregnated celluloseto an acetylating bath of 450 parts acetic anhydrid and 1650 partsbenzene. 1 i

- 8. The process of acetylizing cellulose which consists in treatingcellulose with a hydroxvl containing substance which acts to induceacetyla-tion without altering the cellulose as ,such and is misciblewith the acetylizing bath, a diluent therefor and a non-acid condensingagent, and then subjecting the impregnated cellulose tothe ac.- tion ofa non-solvent acetylating bath.

9. The process of acetylizing. cellulose which consists in treatingcellulose with a hydroXyl-containing substance which acts to induceacetylation without altering the cellulose as such and is miscible withthe acetylizlng bath, a diluent therefor and a concellulose first with anon-acid condensing densing agent consisting of an inorganic salt, andthen subjecting the impregnated cellulose to the action of a non-solventacet ylating bath.

'10. The process of acetylizing cellulose to induce acetylation withoutaltering the .drid and benzene.

treating cellulose with a i which ing cellulose as such and is misciblewith the acetylizing bath, non-acid condensing agent, and thensubjecting the impregnated cellulose to the action of an acetylatingbath of acetic anhyof acetylizing cellulose, which consists in firstimpregnating the cellulose with a preliminary bathicomprismg acondensing agent and an ingredient that will facilitate lateracetyllzation and 11. The process 'then subjecting the treated celluloseto a second bath comprising an acetylating agent without any additionalcondensing agent.

12. The process which consists in treating cellulose with zinc chloridand a diluent which does not, react wlth the cellulose, and

a diluent therefor and a then subjecting the'treated cellulose to anacetylating bath.

13. The process which consists in treating cellulose with zinc chloridand hydrous acetic acid, and then subjecting the treated cellulose to anacetylating bath.

14. The process which consists in treating cellulose with zinc chloridand a diluent does not react with the cellulose, and then subjecting thetreated cellulose to a diluent of said agent inwhich the cellulose isinsoluble. I

-15. The process which consists in treat cellulose with zinc chlorid anda diluent which does not react with thecellulose, and then subjectingthe'trea-ted cellulose to a reactive bath of acetic anhydrid andbenzene.

Y 16. The rocess which consists in treating i cellulose with a non-acidcondensing agent and a hydroxyl containing substance which acts toinduce acetylation without alterin the cellulose as such and is misciblewit reactive bath of an acetylating agent and a the acetylizing bath,both of which are diluted with a diluent which does not react upon thecellulose, and then subjecting the treated cellulose to an acetylatingbath.

17 The rocess which consists in treating cellulose with a non-acidcondensing a cut, and a h droxyl'containing substance w ich acts to,induce acetylation without altering the cellulose as such and ismiscible'with the acetylizin bath, both of which are diluted with a diuent which does not react upon the cellulose, and then subjecting thetreated cellulose to a reactive bath containing an acetylating agent anda diluent of' said agent in which the cellulose is insoluble.

18. The process which comprises treating cellulose with an inorganicsalt which acts as 3 a condensing agent and then with 5.11

acetylizing agent, and a diluent of said'130 acetylizing agent in whichthe cellulose is in- 7 soluble.

acetylizing agent in which the cellulose is insoluble.

21. The-process of acetylizing cellulose which comprises treating thecellulose with zincchlorid and thereafter with an acetylizing agent andbenzene.

22. The. process of acetylizing cellulose which consists intreating-cellulose with a hyd'roxyl .containing substance which acts toinduce acetylation without altering the cellulose as such and ismiscible with the acetylizing bath, a diluent therefor and a non-acidcondensing agent, .and then subjecting the same to the action of anacetylizing bath of acetic anhydridand a diluent therefor in which thecellulose is insoluble.

23. The product which comprises "acetyl cellulose obtained by treatingcellulose with a non-acid condensing agent and a hydroxyl containingsubstance which acts to induce acetylation without altering thecellulose as such and is miscible with the acetylizing bath, both ofwhich are diluted with a di1 uent which does not react upon thecellulose, and then subjecting the treated cellulose to an acetylatingbath.

24. The product which comprises acetyl .cellulose obtained by treatingcellulose with a non-acid condensing agent and a hydroxyl containingsubstance which acts to induce ac'etylation without altering thecellulose as such and is miscible with the acetylizing bath, both ofwhich are diluted with a diluent which does not react upon thecellulose,

- and then subjecting'the treated cellulose to a reactive bath of anacetylizing agent and a diluentof said agent in which the cellulose isinsoluble.

25. The product which comprises acetyl cellulose obtained by treatingcellulose'with a non-acid condensing agent and a hydroXyl containingsubstance which acts to induce acetylation without altering thecellulose as such and is miscible with the acetylizing bath, both ofwhich are diluted with a diluent which does not react upon thecellulose, and then subjecting the treated cellulose to a reactive bathof acetic anhydrid andbenzene.

26. A product ofthe hereinbefore described process comprising an acetylcellulose, the original fibrous structure of the cellulose beingsubstantially unaltered, the

product being obtained without hydrolysis of the cellulose and beingditiicultly but nevertheless soluble in chloroform.

27. The product which comprises acetyl cellulose obtained withouthydrolysis of the cellulose by treating it with a condensing agent and asubstance that acts to facilitate later acetylization and then with anacetylizing bath.

28. The product which comprises acetyl cellulose obtained by treatingcellulose with a non-acid condensing agent and a substance which acts tofacilitate later acetylization and is miscible with the lateracetylizing bath and which does .not perceptibly alter the chemicalcomposition of the cellulose and thereafter subjecting the treatedcellulose to an acetylizing bath.

In testimony whereof I aflix my signature, in presence of two witnesses.

WVILLIAM G. LINDSAl lVitnesses C. V. EDWARDS, C. GALvIoN.

